Goldman's scathing verdict comes after Citi Research began covering GoPro's stock earlier in March. also giving it a sell rating. "GoPro's market-leading action cam products are not enough to overcome the overall decline in standalone imaging products (camcorders / cameras) and increased saturation in mature markets like the US," the bank's analysts wrote. "In the absence of significant topline growth, the company has started to focus on operating expense control, but breakeven remains at least 2 years out, in our view."

In short: Banks are worried that GoPro has reached everyone it's likely going to be able to, and there's no room left for growth — making it a bad choice for investors.

A GoPro spokesperson did not immediately respond to Business Insider's request for comment.

Here's how that stock drop looks, from June 2014 to the present day. It's now a long way from its giddy highs of nearly $100 a share in the months after its IPO.

"In 2016, big investments in hardware, cloud, and mobile yielded a solid foundational experience for our customers," GoPro founder and CEO Nicholas Woodman said in a statement at the time. "In 2017, we will build on this foundation for our customers while improving efficiency and managing cost to achieve profitability."